Additional policemen from the 9th Regional Public Safety Battalion and TGZ have also been scattered in and around the city to conduct checkpoints, Huesca said.

The explosion occurred while security forces are conducting an offensive against the Abu Sayyaf in neighboring Basilan province.

The al Qaeda-linked Abu Sayyaf has been blamed for several bombing incidents in Zamboanga City in the past.

Northern Mindanao alerted

Meanwhile, policemen in the neighboring region of Northern Mindanao were placed under full alert – the highest among three alert statuses – after the explosion in Zamboanga City.

All police units were told to observe the status in light of the IED explosion and “threats of terrorism,” regional police director Chief Superintendent Agrimero Cruz said in a statement.

The full alert status comes with “target-hardening” measures, 24/7 checkpoints, deployment of EOD and K-9 units at bus terminals, maximized police visibility in areas of convergence, and border patrols, he said.

Northern Mindanao is connected to the Zamboanga Peninsula in the west by Misamis Occidental and Lanao del Norte.

The region’s two highly urbanized cities – Cagayan de Oro and Iligan – already experienced bombings by the Abu Sayyaf and other Islamic militants in recent years.

“While the PNP enourages vigilance, the public is advised not to panic… Community members are encouraged to report suspicious individuals and activities to the nearest police station,” Cruz said. (John Roson)